Calendering mechanism and process



March 24, 1931. A. BOSSHARD 1,797,398

CALENDERING MECHANISM AND PROCESS Filed. Nov. 9. 1929 I the Patented Mar. 24, 1931 UNITED STATES PATENT OFFICE,

ARNOLD BOS SHARD, OF ARBON, SWITZERLAND dALEN DERING MECHANISM AND 'PROCESS a puat ionma November 9, 1929, Serial No. 406,086, and in Germany l tarch 11, 1929.

The present invention relates to a novel process and apparatus for calendering or glazing fabrics and more particularly to such a process and apparatus for use in connection 5 with the calendaring or glazing of textiles.

Objects and'advantages of the invention will be set forth in part hereinafter and in partwill be'obvious herefroi'n, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in "the appended claims.

The invention consists in the novel parts, construction, arrangements, combinations and improvements herein shown and described.

The invention consists in the novel steps, processes, means and instrumentalities pointed out in the appended claims.

The accompanying drawings (Figures 1 and 2) represent diagrammatically the steps of the process of the present invention as well as two modified embodiments of the present invention which may be used in carrying out rocess. eretofore, in the glazing or calendering of fabrics, such as textiles, has been generally carried out by passing the fabric between a. plurality of smooth, or slightly-roughened, heated rollers of steel or other material, thereby subjecting the fabric to a very high degree of pressure. In these processes'the extent of the glazing is primarily'gdetermined by the temperature'and the pressure to which the fabric is subjected,. and thehigherthe temperature and pressure, the greater is the glazing resulting from the treatment. When great pressures are employed, however, the

abric becomes crumpled and is thereby injured, and-this crumpling is increased by any! dampness present in the fabric being treated.

The present invention provides aprocess and apparatus by which the disadvantages encountered in connection with prior p rocesses are eliminated, and thedesired glazing is obtained without causing any injury to the textile material or. other fabric.

According to the present preferred process illustrating the present invention, a web of W textile material or other fabricto be glazed or calendered is preferably first heated and thoroughly dried, and is then electrostaticah ly charged, after which, and while the fabric is still heated and before it has had the op portunity to absorb moisture to any substan tial degree, is passed between the heated rolls of the calender, oris otherwise subjected to heat and pressure. 7

Accordingto the present preferred embodiment of the apparatus for carrying out the process of the present invention and forming part of the present invention, there is preferably provided means for heating the fabric to eliminate substantially all the moisture contained therein. Means are also provided for electrostatieallycharging the dried and heated fabric and'passin it to the calendering rolls while it is in ,a ated, dry and electrostatically charged condition. The calendering rolls may be of substantially any suitable form and are preferably quite similar to those now generally employed and may comprise a plurality of rotatably mounted rolls formed of steel or other suitable mate-' rial, heated by suitable means, and pressed together with relatively great,bu t variable pressure and between which the fabric to be glazed is pulled as the rolls are rotated:

Other featuresof the invention will be in-' itially pointed out in connection with the fol- I lowing detailed descriptions of the present preferred embodiment of the invention," and it will be understood that the foregoing general description and the followin detailed descriptionare both exemplary an explanato butnot restrictive of the invention.

eferring now in detail to the accompanying drawings I diagrammatically illustrating the present preferred embodiment of the ap-' paratus of, the present invention by which the steps of the procss are carried out,'the" 1 web 10 of'textile material, or other'fabrie to 'be glazed is first thoroughly dried, and for-J 9 this purpose is passed over and around the drying drums 11, 12 and 13 which'ar'e'formed of steel, or other suitable material, and'are provided with any suitable internal heating means. Drums 11, 12am] .13 are Preferably,

rotated atsubstantially the same peripheral speed Lethe-. 9; theweb 10 and pull the web charging the web of fabric,

from the web roll or other source of supply. Closely adjacent to the drying drums 11, 12 and 13 are the means for electrostatically which may comprise means for frictionally generating a charge on the web. As embodied there are provided a pair of drums 14 and 15, insulated from each other and the surrounding apparatus and provided with a surface of any material suited to the generation of frictional or static electricity as it coacts with the material of the web 10. Preferably, drums 14 and 15 are heated and provided with a shell 16 of insulating material such as hard rubber, which supports an external shell 17 and insulates it from the core of the drum. Drums 14 and 15 are driven at a peripheral speed different from that of the web, and the difference in speed is determined principally by the amount of electricity it is desired to generate for the charging of the fabric web.

After the web has been thoroughly dried and sufiiciently charged with electricity, it is led between the glazing or calendering apparatus, which in the present instance preferably comprise rotatably mounted and driven, cotton or jute-covered rollers 18 and 19 which are urged together by variable pressure and between which the fabric is subjected to heat and pressure. Rollers 18 and 19 are heated, and for this purpose, there are provided rotatably mounted heating drums 20 and 21 contacting with the periphery of the rollers 18 and 19 and constantly heatingthe sur: face of these rollers. Heating drums 20 and 21 may be heated by steam or electricity and are preferably maintained at a temperature of approximately 180 C.

The greater the pressure to which the fabric is subjected, the greater is the glazing of the fabric and the greater must be the electrostatic charge on the web to avoid crumpling of the fabric as it is passed through the calendering rolls.

Under normal operating conditions and where the air of the room in which the apparatus is dry and hot, there is little danger of an excessive amount of the electrical charge on the web being dissipated between the charging and calendering operation,but where the air is damp, additional means should be provided for dissipation of the charge on the web offabric. For this purpose, apparatus similar to that shown in Fig. 2 may be provided. This ap-- paratus closely corresponds to that shown in Fig. 1 and differs principally therefrom in that heating means are provided for maintaining the air heated between the charging drums l i and 15 and calendering rollers 18 and 19. As embodied, there are provided a pair of spaced heating plates 23 and 24, heated by steam or electricity, and between which the web of fabric passes as it is led to the rollers 18 and 19. Heating plates 23 and 24 preventing an unduly rapid substituted for the drums 14 and 15, and the.

necessary electricity can be separately generatcd and transferred to the web 10 by suitable conductors.

What I claim is V 1. A process for glazing fabrics under heat and pressure which comprises drying the fabric, electrostatically charging the fabric and subjecting the fabric to the combined action of heat and pressure while in a dry and electrostatically charged condition.

2. A process for glazing fabrics under heat and pressure which includes electrostatically charging the fabric and subjecting the fabric to heat and pressure while the fabric is electrostatically charged.

v3. A process for glazing fabrics under heat and pressure which comprises electrostatically charging a dried fabric and subjecting the electrostatically charged fabric to heat and pressure.

4. A process for glazing textile fabrics which includes thoroughly drying a web of the textile fabric, electrostatically charging the web of textile fabric, and immediately thereafter and while the textile fabric is dry and electrostatically charged subjecting the fabric to the combined action of heat and pressure.

5. A process for glazing fabrics which includes generating frictional electricity by subjecting the fabric to friction, charging the fabric with the electricity so generated, and calendering the fabric While it is electrically charged.

6. Apparatus for glazing fabrics including in combination heated drums for heating and drying a web of fabrics, drums over which the fabric is pulled to electrostatically charge the fabric, and heated calender rolls between which the fabric is pressed.

7. Apparatus for glazing fabrics including for keeping the fabric electrostatically charged and heated between the charging means and the calender rolls.

8. Glazing apparatus for fabrics including in combination means for heating and drying a .web of fabrlc, means for electrostatically charging the fabric, and means for simultaneously heating and pressing the fabric.

9. Glazing apparatus for fabrics including in combination heated drums over which a web of the fabric is passed, means for electrostatically charging the fabric, and a plurality of, heatedrollers between which the fabric is pressed while electrostatically charged.

10. Glazing apparatus for fabricsincluding in combination means for heating and m drying the fabric, means for electrostatically charging the fabric, means for subjecting the 3 fabric to heat and pressure, and means for preventing dissipation of the electric charge E on the fabric until after the fabric has been 't subjected to heat and pressure. j

11. Glazing apparatus for fabrics including' in combination means for heating and drying the fabric, means for electrostatically charging the fabric, means for subjecting the fabric to heat and pressure, means for preventing absorption of moisture by the fabric between the drying and pressing operations and other means for facilitating the retention of the electric charge on the fabric. 05 12. A process of treating fabrics which comprises electrostatically charging the fabric and immediately thereafter glazing the fabric.

In testimony whereof, I have signed my name to this specification.

ARNOLD BOSSHARD. 

